#include <thread>
#include <algorithm>
#include <iostream>

using namespace std;

int main()
{
    int sum = 0;
    std::thread t1 = std::thread([&](int L, int R){
        while (L <= R) {
            sum += L;
            L++;
        }
        //cout << sum << endl;
    }, 1, 100);
    
    t1.join();
    std::cout << sum << std::endl;
    return 0;
}